There may be others, but Pressac and Austin Taylor do - though these days it would AFAIK actually be for Openreach, BT's off-shoot which deals with the local loop.
The BT NTE5 Master Sockets are made by different companys but all to the same standard. I know one of the most comonly used manufactures of BT is Austin Taylor.
if your asking because you want to put another socket up or replace on just get a standard wall socket they are all standard don't matter who makes them
thanks gents, its amazing what people know. I am asking where because I am an installer and want to buy a load at trade price, so, if you have any other ideas where to get them from( its got to be legal ) it would be most appreciated.
thanks again,
alf